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Updated: Jun 23, 2026
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Linking Predation Risk, Herbivore Physiological Stress and Microbial Decomposition of Plant Litter
Published on: March 12, 2013
Functional links and robustness in food webs
Stefano Allesina1, Antonio Bodini, Mercedes Pascual
1Department of Ecology and Evolutionary Biology, University of Michigan, Natural Science Building, 830 North University, Ann Arbor, MI 48109, USA. jane.memmott@bris.ac.uk
Summary
Ecosystem robustness depends on functional feeding links, not just species hubs. Many redundant links mean even non-hub extinctions can destabilize ecosystems, risking tipping points.
Area of Science:
- Ecology
- Ecological networks
- Conservation biology
Background:
- Ecosystem robustness to species loss is critical amid rising extinction rates.
- Previous studies focused on species (hubs) rather than interactions in food webs.
- Secondary extinctions are a key concern in understanding ecosystem stability.
Purpose of the Study:
- To investigate the role of trophic links, not just species, in ecosystem robustness.
- To differentiate between functional and redundant feeding connections.
- To assess how link redundancy affects ecosystem stability and tipping points.
Main Methods:
- Analysis of empirical food web data.
- Categorization of trophic links based on their contribution to ecosystem robustness.
- In-silico removal experiments to simulate species loss impacts.
Main Results:
- Trophic links can be classified as functional or redundant.
- Species hubs may not be critical if their links are redundant.
- The proportion of functional links is consistently high across diverse ecosystems.
- Ecosystem robustness can decrease significantly due to extinctions that don't cause secondary extinctions.
Conclusions:
- Ecosystem stability is more dependent on the functionality of feeding links than on the presence of highly connected species (hubs).
- Redundant links are common, and their loss can impact ecosystem robustness.
- A high proportion of functional links suggests ecosystems are sensitive to species loss, potentially leading to tipping points and collapse.
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